During a surgical procedure, there is a need for intra-operative pathology consultation to guide immediate surgical decisions such as establishing or confirming a diagnosis; or delineating margins of diseases. These pathological assessments are vital for successful surgical outcomes. Yet, typical intra-operative pathology procedures are time-consuming since tissue biopsy samples have to be transferred to a pathology lab where they have to be correctly prepared and analyzed following which the results need to be adequately communicated to a remote operating room. This long process may cause discontinuities in surgical workflows and delays in surgical actions. Under ideal circumstances, it typically takes approximately 20 minutes to perform a biopsy analysis. However, this interval is usually longer during a surgery and waiting times of more than 60 minutes are not unusual for a variety of reasons. Reasons for delays may include a large distance between the operating room and the pathology lab, limited capacity of the pathology lab to analyze the biopsy sample(s), or inefficient setup of the pathology equipment.
Accordingly, it would be beneficial to provide a biopsy analysis system that can be placed in an operating room, easily operated, and which can provide fast and reliable relevant pathological assessments.
Further, various types of optical imaging can provide information about tissue disease states. Examples of such optical imaging modalities include optical coherence tomography (OCT), incoherent Raman spectroscopy, coherent Raman spectroscopy, auto-florescence intensity imaging, fluorescence lifetime imaging, diffuse optical imaging, confocal microscopy, super-resolution microscopy, second harmonic imaging microscopy, third harmonic imaging microscopy, dark field imaging, phase-contrast microscopy, and white light imaging (e.g. traditional microscopy).
The imaging information can be further improved by injecting imaging contrast agents into an examined tissue. It has also been realized that insights about a tissue can be enhanced if the tissue is probed with several optical imaging modalities and the data from different imaging modalities are correlated. The reason for the success of such multi-modal imaging approaches is that these optical imaging techniques examine different tissue properties, so they are complimentary in nature. Several embodiments of multi-modal optical imaging systems have been reported in academic literature such as the reference Egodage, Kokila, et al. “The combination of optical coherence tomography and Raman spectroscopy for tissue characterization.” Journal of Biomedical Photonics & Engineering 1.2 (2015): 169-177, and disclosed in patents DE19854292C2, U.S. Pat. No. 6,507,747B1, U.S. Pat. No. 7,508,524B2, which are herein incorporated by reference.
A shared feature of all the reported multi-modal optical systems for tissue imaging is that their optical sub-systems related to individual imaging modalities (e.g. OCT, Raman spectroscopy, fluorescence spectroscopy, etc.) share a certain number of optical elements such as optical beam splitters, lenses, or mirrors. Such design approach has its advantages since it leads to compact optical systems. However, there is also a potential disadvantage since the performance of individual imaging modalities is usually sub-optimal since the choice of the characteristics of shared optical elements is a compromise between different requirements for individual imaging sub-systems. For example, in Raman spectroscopy, signals are very weak compared to background and the pump laser power, so optical elements with sharp optical filtering characteristics are required. However, such optical filtering characteristics may not be optimal for other imaging modalities for which excitation and signal spectra may partially overlap with the Raman ones.
An optical multi-modal imaging platform in which various optical imaging modalities don't share common optical elements may provide individual optical imaging data with better quality and thus improve overall information content of the multi-modal imaging process.